👷 Add GitHub Actions prepare release workflow

.github/workflows/prepare-release.yml

@@ -0,0 +1,78 @@
+name: Prepare Release
+
+on:
+  workflow_dispatch:
+    inputs:
+      bump:
+        description: Release bump
+        required: true
+        type: choice
+        options:
+          - major
+          - minor
+          - patch
+      date:
+        description: Release date in YYYY-MM-DD format. Defaults to today.
+        required: false
+        type: string
+
+permissions: {}
+
+jobs:
+  prepare-release:
+    runs-on: ubuntu-latest
+    timeout-minutes: 5
+    permissions:
+      contents: write
+      issues: write
+      pull-requests: write
+    env:
+      PREPARE_RELEASE_VERSION_FILE: typer/__init__.py
+      PREPARE_RELEASE_RELEASE_NOTES_FILE: docs/release-notes.md
+    steps:
+      - name: Dump GitHub context
+        env:
+          GITHUB_CONTEXT: ${{ toJson(github) }}
+        run: echo "$GITHUB_CONTEXT"
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+        with:
+          persist-credentials: true
+      - name: Set up Python
+        uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 # v6.2.0
+        with:
+          python-version-file: ".python-version"
+      - name: Install uv
+        uses: astral-sh/setup-uv@08807647e7069bb48b6ef5acd8ec9567f424441b # v8.1.0
+        with:
+          # Before upgrading uv version, make sure astral-sh/setup-uv knows its checksum.
+          # See: https://github.com/astral-sh/setup-uv/issues/851#issuecomment-4282017837
+          version: "0.11.4"
+      - name: Prepare release
+        id: prepare-release
+        env:
+          PREPARE_RELEASE_BUMP: ${{ inputs.bump }}
+          PREPARE_RELEASE_DATE: ${{ inputs.date }}
+        run: |
+          uv run python scripts/prepare_release.py prepare
+          version="$(uv run python scripts/prepare_release.py current-version)"
+          echo "$version"
+          echo "version=$version" >> "$GITHUB_OUTPUT"
+      - name: Create release pull request
+        env:
+          GH_TOKEN: ${{ github.token }}
+          VERSION: ${{ steps.prepare-release.outputs.version }}
+        run: |
+          set -euo pipefail
+          branch="release-${VERSION}-${GITHUB_RUN_ID}"
+          git config user.name "github-actions[bot]"
+          git config user.email "github-actions[bot]@users.noreply.github.com"
+          git switch -c "$branch"
+          git add $PREPARE_RELEASE_VERSION_FILE $PREPARE_RELEASE_RELEASE_NOTES_FILE
+          git commit -m "🔖 Release version ${VERSION}"
+          git push --set-upstream origin "$branch"
+          gh pr create \
+            --base master \
+            --head "$branch" \
+            --title "🔖 Release version ${VERSION}" \
+            --body "Prepare release ${VERSION}." \
+            --label release

scripts/prepare_release.py

@@ -0,0 +1,156 @@
+"""Prepare a release by updating the package version and release notes."""
+
+import re
+from datetime import date
+from pathlib import Path
+from typing import Annotated, Literal
+
+import typer
+
+VERSION_PATTERN = re.compile(r'(?m)^__version__ = "(\d+\.\d+\.\d+)"$')
+RELEASE_NOTES_HEADER = "# Release Notes\n\n"
+LATEST_CHANGES_HEADER = "## Latest Changes"
+BumpType = Literal["major", "minor", "patch"]
+
+app = typer.Typer()
+
+
+def parse_version(version: str) -> tuple[int, int, int]:
+    match = re.fullmatch(r"\d+\.\d+\.\d+", version)
+    if not match:
+        raise ValueError(f"Invalid version: {version!r}. Expected format: X.Y.Z")
+    major, minor, patch = version.split(".")
+    return int(major), int(minor), int(patch)
+
+
+def get_current_version(content: str, version_file: Path) -> str:
+    matches = list(VERSION_PATTERN.finditer(content))
+    if len(matches) != 1:
+        raise RuntimeError(
+            f"Expected exactly one __version__ assignment in {version_file}, "
+            f"found {len(matches)}"
+        )
+    return matches[0].group(1)
+
+
+def bump_version(version: str, bump: BumpType) -> str:
+    major, minor, patch = parse_version(version)
+    if bump == "major":
+        return f"{major + 1}.0.0"
+    if bump == "minor":
+        return f"{major}.{minor + 1}.0"
+    return f"{major}.{minor}.{patch + 1}"
+
+
+def update_version_file(content: str, version: str, version_file: Path) -> str:
+    current_version = get_current_version(content, version_file)
+    if parse_version(version) <= parse_version(current_version):
+        raise RuntimeError(
+            f"New version {version} must be greater than current version {current_version}"
+        )
+    return VERSION_PATTERN.sub(f'__version__ = "{version}"', content, count=1)
+
+
+def update_release_notes(
+    content: str, version: str, release_date: date, release_notes_file: Path
+) -> str:
+    if not content.startswith(RELEASE_NOTES_HEADER):
+        raise RuntimeError(
+            f"{release_notes_file} must start with {RELEASE_NOTES_HEADER!r}"
+        )
+    if re.search(rf"^## {re.escape(version)}(?: \([^)]+\))?$", content, re.M):
+        raise RuntimeError(f"Release notes already contain a section for {version}")
+
+    latest_header = f"{RELEASE_NOTES_HEADER}{LATEST_CHANGES_HEADER}\n"
+    if not content.startswith(latest_header):
+        raise RuntimeError(f"{release_notes_file} must start with {latest_header!r}")
+
+    release_header = f"## {version} ({release_date.isoformat()})"
+    return content.replace(
+        latest_header,
+        f"{RELEASE_NOTES_HEADER}{LATEST_CHANGES_HEADER}\n\n{release_header}\n",
+        1,
+    )
+
+
+@app.command()
+def prepare(
+    bump: Annotated[
+        BumpType,
+        typer.Argument(
+            envvar="PREPARE_RELEASE_BUMP",
+            help="The release bump to make: major, minor, or patch.",
+        ),
+    ],
+    version_file: Annotated[
+        Path,
+        typer.Option(
+            envvar="PREPARE_RELEASE_VERSION_FILE",
+            exists=True,
+            file_okay=True,
+            dir_okay=False,
+            readable=True,
+            writable=True,
+            help="Path to the Python file containing the __version__ assignment.",
+        ),
+    ],
+    release_notes_file: Annotated[
+        Path,
+        typer.Option(
+            envvar="PREPARE_RELEASE_RELEASE_NOTES_FILE",
+            exists=True,
+            file_okay=True,
+            dir_okay=False,
+            readable=True,
+            writable=True,
+            help="Path to the release notes Markdown file.",
+        ),
+    ],
+    release_date: Annotated[
+        str,
+        typer.Option(
+            "--date",
+            envvar="PREPARE_RELEASE_DATE",
+            help="Release date in YYYY-MM-DD format. Defaults to today.",
+        ),
+    ] = date.today().isoformat(),
+) -> None:
+    parsed_release_date = date.fromisoformat(release_date or date.today().isoformat())
+
+    version_file_content = version_file.read_text()
+    release_notes_content = release_notes_file.read_text()
+    version = bump_version(
+        get_current_version(version_file_content, version_file), bump
+    )
+
+    version_file.write_text(
+        update_version_file(version_file_content, version, version_file)
+    )
+    release_notes_file.write_text(
+        update_release_notes(
+            release_notes_content, version, parsed_release_date, release_notes_file
+        )
+    )
+
+    typer.echo(f"Prepared release {version} ({parsed_release_date.isoformat()})")
+
+
+@app.command()
+def current_version(
+    version_file: Annotated[
+        Path,
+        typer.Option(
+            envvar="PREPARE_RELEASE_VERSION_FILE",
+            exists=True,
+            file_okay=True,
+            dir_okay=False,
+            readable=True,
+            help="Path to the Python file containing the __version__ assignment.",
+        ),
+    ],
+) -> None:
+    typer.echo(get_current_version(version_file.read_text(), version_file))
+
+
+if __name__ == "__main__":
+    app()